refactor: review Swift codes for chapter_computational_complexity art… (#396)

* refactor: review Swift codes for chapter_computational_complexity articles

* Update time_complexity.swift

* Update time_complexity.swift

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/swift/chapter_computational_complexity/leetcode_two_sum.swift

@@ -33,6 +33,7 @@ func twoSumHashTable(nums: [Int], target: Int) -> [Int] {
 
 @main
 enum LeetcodeTwoSum {
+    /* Driver Code */
     static func main() {
         // ======= Test Case =======
         let nums = [2, 7, 11, 15]

codes/swift/chapter_computational_complexity/time_complexity.swift

@@ -88,7 +88,7 @@ func expRecur(n: Int) -> Int {
 }
 
 /* 对数阶（循环实现） */
-func logarithmic(n: Int) -> Int {
+func logarithmic(n: Double) -> Int {
     var count = 0
     var n = n
     while n > 1 {
@@ -99,7 +99,7 @@ func logarithmic(n: Int) -> Int {
 }
 
 /* 对数阶（递归实现） */
-func logRecur(n: Int) -> Int {
+func logRecur(n: Double) -> Int {
     if n <= 1 {
         return 0
     }
@@ -112,7 +112,7 @@ func linearLogRecur(n: Double) -> Int {
         return 1
     }
     var count = linearLogRecur(n: n / 2) + linearLogRecur(n: n / 2)
-    for _ in 0 ..< Int(n) {
+    for _ in sequence(first: 0, next: { $0 < n - 1 ? $0 + 1 : nil }) {
         count += 1
     }
     return count
@@ -158,9 +158,9 @@ enum TimeComplexity {
         count = expRecur(n: n)
         print("指数阶（递归实现）的计算操作数量 = \(count)")
 
-        count = logarithmic(n: n)
+        count = logarithmic(n: Double(n))
         print("对数阶（循环实现）的计算操作数量 = \(count)")
-        count = logRecur(n: n)
+        count = logRecur(n: Double(n))
         print("对数阶（递归实现）的计算操作数量 = \(count)")
 
         count = linearLogRecur(n: Double(n))

docs/chapter_computational_complexity/time_complexity.md

@@ -138,7 +138,7 @@ $$
 
     ```swift title=""
     // 在某运行平台下
-    func algorithm(_ n: Int) {
+    func algorithm(n: Int) {
         var a = 2 // 1 ns
         a = a + 1 // 1 ns
         a = a * 2 // 10 ns
@@ -340,19 +340,19 @@ $$
 
     ```swift title=""
     // 算法 A 时间复杂度：常数阶
-    func algorithmA(_ n: Int) {
+    func algorithmA(n: Int) {
         print(0)
     }
 
     // 算法 B 时间复杂度：线性阶
-    func algorithmB(_ n: Int) {
+    func algorithmB(n: Int) {
         for _ in 0 ..< n {
             print(0)
         }
     }
 
     // 算法 C 时间复杂度：常数阶
-    func algorithmC(_ n: Int) {
+    func algorithmC(n: Int) {
         for _ in 0 ..< 1000000 {
             print(0)
         }